Shock absorber



Nov. 6, 1928.

J. R. SNYDER SHOCK ABSORBER Original Filed Aug. 9, 1924 Patented Nov. 6, 1928.

omreo STATES JACOB R. SNYDER, or CLEVELAND, orrro, ASSIGNOR To THE STAR REBOUND con- PATENT OFFICE. j

TROLLER column; or CLEVELAND, 01110, Aconronnrron or onto.

SHOCK ABSORBER.

Original application filed Augusta, 1924, Serial No. 731,014. Divided and this application filed August 9, i 1924, Serial No. 731,015.; Renewed ltlarch 31, 1928 This invention relates to shock absorbers adapted particularly for use on motor vehicles to check the rebound following the compression stroke of the main spring.

'More particularly theinvention .relatesto shock absorbers of the frictionally retarded type wherein there is a frictionally retarded drum onto which a strap or belt is wound on the compression strokeof the main springs, and from which it is unwound during, the rebound movement.

A shock absorber of this general type is illustrated in my prior Patent No. 1,502,755,

granted J Ely-29, 1924, but in these shock obsorbers as heretofore marketed, all move ments of the drum inboth directions are frictionally retarded, this being generally accomplished as in my prior patent, referred to, by the use of a one-piece drum, preferably of oil impregnated wood, andaa pair of friction disks which yieldingly engage opposite sides of the drum and bear against thesame with predetermined pressure which can be adjusted at will to vary the friction or retarding action. 1

The principal object of the present inven tion is to provide a construction wherein there is a neutral zone in the sense that the drum may have a predetermined rotation be fore the friction means takes efiect, thus permitting minor relative movements between the car body and axle to take place without being influenced by the shock absorber.-

The present application is a division ofan application, Serial No. 731,014, filed by-me,

said application illustrating certain novel features of a shock absorber of this general type in different forms or en1bodiments,gone of which is specifically claimed herein.

It is a feature of the present invent-ion that acomposite drum is utilized, composed of one or more parts engaged by the friction means, and another part which is engaged by the strap, a predetermined free relative movement being permit-ted between these members before an engagement takes place which causes the movement of one to be transmitted to the other; 4

The invent-ion maybe further briefly sum marized as consisting in certain novel details of construction, and combinations and arrangements of parts which will be described in the specification and set forth in the appended claims. r i

In the accompanying sheet'of drawings ile lustrating the preferred embodiment and a slight modification, F ig. 1 is a sectional view of the improved shock absorber; Fig. 2 is a side elevation with parts in section ;=Fig.-3 is a view looking at the inner side of the drum with partsbroken away Fig. 4C is a similar view showing a modification; and Fig, 5 is a sectional View substantially along the line 55 of B 1g, l, showing a, port-ion only of the,

device.

. Referring now to the drawings, 10 represents a stationary center bolt having-in this instance an enlarged middle portion 10?, preferably hexagonal in section, andat one side of the same a threaded reduced portion l0 rwhich receives a nut 11 and adapted to receive also a fitting by which theshockabsorber may be attached to thechassis frame of a'velncle. At the opposite side of the enlarged middle port-ion 10 is a threaded portion 10, which receives a nut, 12, to be referred to presently. Fitted onto the enlarged middle portion 10 of the center bolt is a nonrotatable collar13 which is preferably formed in two halves for convenience in assembly.

This collar serves as a support for the spiral spring 14, the inner end ofthe spring being receivedin a slot or notch of the collar or being otherwise secured thereto so as to be held stationary. Additionally this collar 13 serves as one of the supports or bearings for the drum, which in this case is hollow and houses the spring 14:, the drum being cont posed of two inner members 15, preferably of voilVimpregnated wood or self-lubricating material and an outer metal portion which receives a. strap 16. The outer meta-l por tion may be formed in one piece or in two or three pieces, but preferably is composed of two side members 17 and an outer band '18 which extends between the side member-sand is secured thereto, the strap 16 being con-' Additionally, the disks 1? are preferably given a compound curve between the wooden disks and the band 18; that is to say, they curve outwardly to form annular seats or shoulders 17 which engage the peripheral portions of the wooden disks or side members 1:"); then they curve inwardly and then again outwardly to form annular seats or shoulders 17 for the band 18. lVith this construction the outer metallic portion of the drum has a good hearing or seat on the inner or wooden portions and practically an oiltight construction is provided where the band 18 is united to the disks 17 so as to prevent the loss of lubricant. as more fully explained in my prior application referred to above.

The band 18 may be formed from a strap of metal, the ends of which are preferably united by bending them outwardly and welding them together, forming an outstanding protuberance 18 (shown in Fig.

The outer end of spring 14 and the inner end of strap 16 can be secured to the band 18 of the drum by a single bolt or equivalent device 19, the protuberance 18 serving to prevent the strap 16 being fastened to the bolt and extended around the drum in the wrong direction.

The metal disks 17 are not positively or rigidly fastened to the wooden disks 15, but are capable of rotating a predetermined amount relatively to the latter, the frictional engagement between the parts permitting this predetermined relative movement when the shock absorber is in action. However, after this predetermined relative movement or predetermined free and nnretarded movement of the outer metallic portion of the drum takes place, it is desirable that the parts be locked together so as to move in unison. This result can be accomplished in different ways, as for example. by providing on the inner sides of the wooden disks 15, preferably at a. plurality of points in each of them, are shaped notches or slots 20 and by depressing the metal disks 1? to form outwardly extending shoulders 21 of less arcuate extent than the notches 20, which shoulders extend into the notches as illustrated, in Figs. 1 and 3. Obviously the outer metal portion of the drum can be turned relative to the inner wooden portion in either direction from the center position. until the shoulders 21 engage the shoulders formed by the ends of the notches 20, and after this occurs the movement of the outer portion of the drum will be transmitted to the inner portion.

Instead of forming the shoulders 21 by pressing the metal outward, these shoulders could be formed by attaching suitable shoulder forming pieces to the outer sides of the disks 17, as for example. studs 22 adapted to extend into are shaped slots 23 of the wooden disks.

The drum is designed to be friction-ally retarded by stationary metal disks 24 which engage the outer sides of the wooden disk 15 and extend inwardly for a distance over their peripheries so as to exclude dirt, dust and the like from their engaging surfaces. The right hand disk 2 1 (as the device is viewed in Fig. 1) is clamped between the nut 11 and a shoulder of the center bolt; the other disk 21 is in sliding engagement with the enlarged middle portion of the center bolt 1t" and is pressed yieldingly inward against the adjacent wooden disk 15 so as to press the Opposite wooden disk 15 against the adjacent friction disk 21 by means of an adjustable spring preferably in the form of a star spring 25, the tension of which can be adjusted by the nut 12 which is screwed onto the end 10" of the center bolt. as previously explained. The inner part of this friction disk may be flanged inwardly to form an extended hearing or seat on the non-circular middle portion 10 of the center bolt so as to minimize back lash or play.

A disk 26 which is between the. st ar spring and nut 12 conceals the major portion of the star spring. the center part of the disk 26 being preferably cupped to receive the nut 12 so that it will turn with the nut. By providing disk 26 with an indicating mark such as shown at 27 in Fig. 2. the position of this disk shown by the position of indicator 2? will indicate the tension which is imposed in the star spring 25.

Lubricant can be supplied to the inner portion of the drum through a passageway 28 in the center bolt, this passageway being normally closed by a plug 29. Lubricant may pass from this passageway through the collar 13 into the drum. To prevent loss of lubricant around the inner part of the drum. felt washers 30 may be provided between the collar 13 and the friction disks 24, substantially as shown in Fig. 1.

Vhen the shock absorber is applied to a vehicle the center bolt 10 is Secured to the chassis frame and the outer end of the belt or strap 16 is suitably secured to the axle, so that during the COIUPILSSlOIl stroke of the main springs of the vehicle the spiral spring 11 will turn the drum so as to wind the strap 16 thereon and keep it taut. On the subsequent rebound stroke the strap 16 is pulled out or unwound from the drum, this being resisted by the spring 14, and by the friction imposed by the friction disks 24. However, with the present construction minor vibrations may occur, as when the vehicle is running over a smooth or fairly smooth road without bringing the friction retarding means into action since the outer part of the drum to which the spring 14- and strap 16 are connected is capable of a given rotation before the movement of the outer part of the drum is ii'nparted to the inner part which is engaged by the friction members. But when the relative movement between the car Inn.

body and axle exceeds a predetermined.

details Shown, but aim in my claims to cover all modifications which do not involve a departure from the spirit and scope of my invention as defined in the appended claims. Havin described my invention, I claim 1. A shock absorber comprising a drum, a strap engaging the same, the drum having a portion which is rotatable in opposite directions and whose movement is frictionally resisted and with respect to which the strap engaged portion of thedrum is capable of a limited free movement.

A shock absorber comprising a drum composed of a portionengaged by a. spring to rotate it in one direction and by a strap to rotate it in the opposite direction, and a frictionally retarded portion rotatable in opposite directions by and having a lost motion connect-ion with the first mentioned portion.

3. A shock absorber comprising a drum having a frictionally retarded inner portion having a lost motion connection withan outer portion for rotating it in opposite directions, and a spring and strap engaging the outer portion. g

4. A shock absorber comprising a portion composed of self-lubricating material, a. friction member engaging it, a metallicportion having a lost motion connection with the first portion for rotating it in opposite directions,

and a spring and strap engaging the metallic portion.

5. A shock absorber comprising a rotatable drum composed of a pair of spaced inner fric tionally retarded members, and an outer portion having a lost motion connection with the inner members for rotating them in opposite directions, and a spring and strap engaging the outer portion.

6. A shock absorber comprising a hollow drum composed of a pair of spaced members of self-lubricating material, an outer metallic portion having a lost motion connection therewith, friction means engaging theinner portion, a spring within the drum and connected to the metallic portion, and a strap engaging the periphery of the metallic portion.

In testimony whereof, I hereunto affix my signature.

JACOB R. SNYDER. 

